Avalanche Forecast

Issued: Feb 22nd, 2016 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Wind Slabs and Persistent Slabs.

deryl kelly, Parks Canada

Jasper.

Intense solar radiation will raise localized hazard ratings on south aspects. Heads up on these aspects late in the day.

Summary

Weather Forecast

Blue skis and cool temps. Overnight lows near or below -15C. Light to moderate Southwest winds.

Snowpack Summary

15 to 20cms of localized HST in sheltered locations at TL over a supportive mid-pack. This is sitting on a weak basil facet layer. BTL, the HS is more inconsistent in depth and support. Solar aspects have a thin sun crust down 20cms and producing moderate to hard resistant compression test results.Â

Avalanche Summary

Activity observed in field trips today seem to be the result of cornice failures triggering the basil weakness in the snowpack. All observations are thought to be 3 to 4 days old or older. Occurring mostly in features where there is obvious loading and in steeper gullies from the Alpine.

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Wind Slabs

Wind slabs are bonding well, however caution is still warranted in immediate lees and cross loaded terrain above treeline.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

Persistent weak layers of decomposed surface hoar, facets, and depth hoar can be found in many locations. Although these layers have been stubborn to trigger underfoot but, will trigger with a heavy load, like cornice failure.

Carefully evaluate terrain features by digging and testing on adjacent, safe slopes. Avoid steep slopes below cornices.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Feb 23rd, 2016 4:00PM